<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<input type="text" value="frank" abc="tom" autofocus>

<div>aaa</div>
<script>

   var inputObj = document.getElementsByTagName('input')[0];
   inputObj.abce = 'frank';


   window.onload = function(){
       var lis = document.getElementsByTagName('li');
       for(var i = 0;i<lis.length;i++){
           lis[i].onclick = function(){
               //this
               alert(this.title)//this等于当前被点击的对象
           }
       }
   }
</script>

<ul>
    <li teader="frank" title="mm">
        A班
    </li>
    <li teader="tom"  title="nn">
        B班
    </li>
</ul>
</body>
</html>